Conveyer apparatus

ABSTRACT

The present invention relates to a conveyor apparatus which comprises an endless slat conveyor which provides an air suction chamber, a pair of chains surrounding the air suction chamber, a plurality of slats extended between the chains, the slats having air suction ports and, if required, an elastic plate, and a plurality of driving sprockets to drive the endless slat conveyor; an endless backup belt which provides a pair of toothed belts (e.g. chains), the belts being maintained in intimate contact with the edges of the slats, and an airtight wide membrane extended loosely between a pair of the toothed belts (e.g. chains); and an air suction device which has an air suction tube connected to the air suction chamber and a blower. This conveyor apparatus is made up of a horizontal part and a vertical or inclined part. Articles supplied on the slats of the horizontal part are covered entirely by the airtight membrane and the membrane is sucked to the surface of the articles when the pressure in the space formed between the slat conveyor and the backup belt drops in the negative. Consequently, the articles are able to be conveyed in the vertical or inclined direction, while holding securely in a sense sandwiched between the slat conveyor and the backup belt.

United States Patent [72] Inventors Tohei Okano;

Takehiko Kannari. both'of Osaka, Japan [2 l] Appl. No. 880,134 [22]Filed Nov. 26, 1969 [45] Patented Sept. 7, 1971 [73] Assignee TheTsubakimoto Chain Manufacturing Co., Ltd. Jotoku, Osaka, Japan [32]Priority ,Ian. 6, 1969 [33] Japan [31 32/1969 [54] CONVEYER APPARATUS 6Claims, 11 Drawing Figs. [52] U.S. Cl 198/162 [51] lnt.Cl r v B65gl5/14[50] Field of Search 198/162, 165

[56] References Cited I UNITED STATES PATENTS 2,97 l ,632 2/196] Sauveel 98/165 Primary Examiner-Edward A. Sroka At10rney-Woodhams, Blanchardand Flynn ABSTRACT: The present invention relates to a conveyorapparatus which comprises an endless slat conveyor which provides an airsuction chamber, a pair of chains surrounding the air suction chamber, aplurality of slats extended between the chains, the slats having airsuction ports and, if required, an elastic plate, and a plurality ofdriving sprockets to drive the endless slat conveyor; an endless backupbelt which provides a pair of toothed belts (e.g. chains), the beltsbeing maintained in intimate contact with the edges of the slats, and anairtight wide membrane extended loosely between a pair of the toothedbelts (e.g. chains); and an air suction device which has an air suctiontube connected to the air suction chamber and a blower. This conveyorapparatus is made up of a horizontal part and a vertical or inclinedpart. Articles supplied on the slats of the horizontal part are coveredentirely by the airtight membrane and the membrane is sucked to thesurface of the articles when the pressure in the space formed betweenthe slat conveyor and the backup belt drops in the negative.Consequently, the articles are able to be conveyed in the vertical orinclined direction, while holding securely in a sense sandwiched betweenthe slat conveyor and the backup belt.

PATENTEDSEP mu 3,603,448

SHEET 2 OF 6 WA KM 1% PATENTED SEP 719m sum u or 6 FIG.5

CONVEYIER APPARATUS BACKGROUND OF THE INVENTION When shaped articles,such as various sized packed articles boxes or bags, etc., orplate-shaped articles, such as metal or plastics, etc., are conveyedvertically, there has not, hitherto, been found a conveyor apparatuswhich conveys these articles in succession along the vertical orinclined passage, while securely holding the articles in position asthey are conveyed, without giving any kinds of damages to the articles.

SUMMARY OF THE INVENTION This invention relates to a conveyor apparatuswhich comprises an endless slat conveyor which provides an air suctionchamber, a pair of chains surrounding the air suction chamber and aplurality of slats with air suction ports extended between the chains;an endless backup belt which provides a pair of toothed belts (e.g.chains) and an airtight wide membrane extended loosely between a pair ofbelts; and an air suction device.

An object of the present invention is to provide a conveyor apparatuswhich is able to convey various sized or shaped articles safely andsuccessively due to covering the articles put on an endless slatconveyor by an endless backup belt.

Another object of the invention is to provide a conveyor apparatus inwhich articles are sucked to an endless slat conveyor by an air suctiondevice and are conveyed along the vertical passage in order to savespace and to reduce conveying time.

Moreover, in a case that an elastic plate is secured on an endless slatconveyor, articles can be conveyed without any damage, as the articlesare put on the soft surface of the elastic plate.

BRIEF DESCRIPTION OF THE DRAWINGS This invention will now be furtherdescribed with reference to the accompanying drawings in which:

FIG. 1 is a perspective view of a conveyor apparatus of the invention;

FIG. 2 is a side view of FIG. 1;

FIG. 3 illustrates an air suction chamber in detail FIGS. 4 and 5 aresectional views taken along the line A-A of FIG. 1;

FIGS. 6 and 7 are sectional views of a tooth of an endless backup beltand a sprocket and a bearing of an endless slat conveyor;

FIGS. 8, 9, I0 and 11 are views describing the principle of operation ofthe invention.

Referring to FIGS. 1 and 2, a conveyor apparatus according to thepresent invention comprises an endless slat conveyor which provides anair suction chamber 1, a pair of chains 2 surrounding the air suctionchamber 1, a plurality of slats 3 extending between the chains 2, anddriving sprockets 9 for driving the endless slat conveyor; an endlessbackup belt which comprises a pair of toothed belts 11 (e.g. a pair ofchains), the belts 11 being maintained in intimate contact with theedges of the slats 3, and an airtight soft and wide membrane 112extending loosely between the belts 11; and an air suction device whichprovides an air suction tube 15 connected to the air suction chamber 1and a blower 16. The slat conveyor, the backup belt, driving mechanism22 of slat conveyor and a motor 21 are respectively mounted on a frame20.

As is readily apparent from FIGS. 1-4 and more particularly from FIGS. 3and 4, the chains 2 of endless slat conveyor are extended betweensprockets 9 and 9 to surround the air suction chamber 1. Rollers 8 ofchain 2 are guided by a guide rail 6 mounted on the frame as shown inFIG. 3. The both edges of slats 3 are connected to the rollers 8 throughL-shaped members by bolts 17, the slat 3 having air suction ports orslits 5. The air suction chamber 1 is enclosed by a channel-shapedmember 111 at the left, right and back sides. Airtight members 7 aresecured to the both sides of channel-shaped members facing to the slat 3by bolts 19 through plates 18, the extremity of airtight member 7 beingcontacted to the surface of slat 3. On the underside of slat 3, theairtight membrane 12 is contacted tightly as shown in FIG. 3. Thus, thechannelshaped member 111, the airtight member 7, the slat 3 and themembrance 12 make the air suction chamber 1 airtight.

The backup belt consists of a couple of endless toothed bolts 11 and theendless membrane 12, and is extended between gears 10 and 28 throughintermediate gears 28 as shown in FIGS. land 2. The airtight membrane 12is wide and soft so as to be deformed easily in obedience to the shapeof an article to be wrapped. The membrane 12 is extended loosely betweena pair of the belts 11 as shown in phantom line in FIG. 4. The teethsecured to the belt 111 are held between a rail 13 provided on the frame20 and a guide member 32 attached to the underside of the slat 3. Thusthe movement of backup belt in the direction ofleft and right is[limited The toothed wheels (e.g. sprockets) 10 and 28 are respectivelysecured to projecting shafts 27 and 31. The shaft 27 is connected to amain shaft 24 through sprockets 29 and 30 as shown in FIGS. 1 and 2. Thesprockets 29 and 30 are designed to drive the belts 12 and the chains 2with the same speed.

Referring to FIG. 6, the projecting shaft 27 or 31 is mounted onbearings 26 provided on the frame 20, and has the toothed wheel (e.g.sprocket) 10 or 28 on one hand and a wheel on the other hand. Since theprojecting shaft 27 or 31 is free at the right or left end respectively,the membrance 12 connected to the shaft 27 or 31 through the toothedwheel (e.g. sprocket) 10 or 28 is flexible freely in the direction ofthe arrows within the width of the belt 11 in FIG. 6.

The air suction tube 15 connected to the suction port of blower 16 isconnected to the suction side 14 of the air chamber 1 in order to suckair from the air chamber 1 which is closed up airtightly by thechannel-shaped member, the slats 3 and the other members. Accordingly,the air suction of blower 16 results in sucking the airtight membrane 12of the backup belt as shown in phantom line in FIG. 4, or sucking themembrane 12 with articles M as shown in solid line in FIG. 5, to thesurface of slats 3. The principle of the suction operation in accordance with the present invention is as follows.

Referring to FIG. 8, in a case where a smooth plate-shaped article M isdisposed to the left side (when viewed as in the drawing) of a verticalsuction plate 3 which has air suction ports 5, and when the pressure ina closed room which is provided on the right side of the plate 3 isdropped by air suction, the article M is pushed to the suction plate 3by the force (Po- P)AL: where; P0 is the atmospheric pressure, P is thepressure in the space A and L are the sizes of article M as shown inFIG. 9.

Then, a condition in which the article is to be held on the suctionplate 3 may be written as:

aw -H L: W (1) where ,u. is the coefficient of friction between thearticle M and the suction plate 3 W is the weight of articles M. Thatis, if the pressure P enough to satisfy the formula l is given, thearticle M is able to be held on the suction plate 3.

However, as the article M has unevenness on the surface to some extenteven if it is seen to be smooth at a glance, there are inevitably someextremely small space between the article M and the suction plate 3.Then the sufficient condition of suction is not suitable in the formula(I) but may be as follows:

a,u(Po-P)ALZ W 2 where a is the coefficient which is decided by theshape and the size of space between the article M and the suction plate3. Judging from the formula (2), it is easily understood that it iseconomical and desirable to approximate the value a to the value I. Oneof the devices to attain the object mentioned above is shown in FIG. 10.A soft and elastic member 4 is stuck on the left side of suction plate 3and a plate-shaped article M having uneven surface is disposed on theelastic member 4. In this case, as the negative pressure exerted to thearticle M pushes it into the elastic member 4, the article M and theelastic member 4 are sucked toward each other as if they were completelysmooth, or in the similar condition. However, in a case that theunevenness of article is so large, it is difficult to find such asuitable elastic member.

Accordingly, a basic conception of this invention is to cover an articleM completely with an airtight soft and wide membrance 12 for sucking thearticle M to the suction plate 3 as shown in FIG. 11. Under thiscondition, there is produced the closed space between the membrane 12covered on the article and the suction plate 3. When air in the room issucked, the pressure in the closed space drops, thereby the membrane 12pushes the article M to the suction plate 3.

In the example shown above, the condition of equilibrium of forces thatthe article does not fall down from the suction plate may be as follows:

JA Z W where a; P0, P, W, A and L are identical in the formula (1).

In this case, it is necessarily to consider that the article M isinclined to revolve and fall down around the corner by thecounterclockwise movement (when viewed as in the FIG. 11). The conditionof equilibrium of movement to prevent it may be as follows:

/(PP)AL" WH (4) where H is the length between the center of gravity ofthe article M and the suction plate 3. Therefore, the condition in whichthe article is able to be held on the suction plate is to satisfy theconditions of equilibrium of the formula (1) and (2) simultaneously.

When the blower 16 starts its operation in FIGS. 1 and 2, air in the airchamber 1 is sucked into the blower through the air suction tube 15 andthe pressure P in the air chamber becomes lower than the atmosphericpressure. Consequently, the pressure equivalent to the amount that thenegative pressure in the air chamber 1 times the whole area of the slats3 is exerted on the slats. Then the soft and wide membrane 12, extendingloosely between the left and right belts 11 with gear teeth in parallelwith the slats 3, is sucked to the slats 3 through the air suction ports5.

Referring to FIG. 1, the down left portion of the slat conveyor isarranged horizontally, the slat conveyor being driven in the directionof the arrow (or in the opposite direction, if required). The toothedbelt 11 on which the airtight wide and soft membrane 12 is looselyextended is guided by the sprockets l0 and 28 and the rail 13 providedon the frame 20. The article M carried on the slats 3 at the point Salong the direction of the arrow advances between the sprockets 28located on the left and right sides, while the airtight membrane 12 iscovering the article therein. When advancing into the region of the rail13, the article is completely wrapped up by the airtight membrane 12.

Thus, when covering the left and right sides, the front and back sidesand the bottom of the article M as shown in FIG. 5, the membrane 12 issucked to the air chamber 1 in the state of wrapping the article M, thislatter being pushed to the slats 3. Therefore, assuming the pressure inthe air chamber is sucked so as to satisfy the conditions in theformulas (3) and (4), the article M is able to be held on the slats 3.

Then, when the sprockets 9 and 10 are driven by the motor 21, thetoothed belt 11, the membrane 12 and the article M wrapped by themembrane 12 are moved together at the same speed.

The membrane 12 described above should be so soft and wide that it isable to cover different shapes of articles and to be sucked to the slatseasily. Therefore, the membrane should have low air permeabilitydurability for repeated bending and large tensile strength, and suchnature should be constant for the change of temperature and the passageof time. For instance, chemical fiber textile coated with a rubberlikematerial, such as rubber or plastics is preferable.

In a case that an article to be conveyed is a plate which is not sothick, it is enough when the width of membrane is larger than the lengthwhich adds the width of plate to its thickness. In the case of solidarticles, the width of which is H, it is suitable when the width ofmembrane for one of the articles is larger than the length which addsthe width of article to 2H, and the length of membrane is larger thanthe length which adds the length of belt 11 to 2H.

The toothed belt 11 should be maintained in intimate contact with theleft and right edges of the slats 3 and keep airtight. Moreover, theyshould be conveyed so as to be moved together with the slat conveyor andso not to produce the unbalance between the left and right edges. Theteeth should be engaged with the teeth without slipping between them. Itis convenient to use a well-known chain shown in FIG. 3, as the toothedbelt.

Additionally, it is effective to use an elastic plate which is stuck onthe slats 3. Soft material, such as foam rubber or plastics, ispreferable as the elastic plate. This elastic plate prevents damagewhich occurs by the contact between the article M and the slats 3, andgets reliable suction by being contacted with the surface of articlewhich has an unevenness.

While I have shown and described certain specific embodiment of myinvention, I am aware that many modifications thereof are possible. Myinvention, therefore, is not to be limited to the precise details shownand described but is intended to cover all modifications coming withinthe scope of the appended claims.

We claim:

1. A conveyor apparatus, comprising:

conveyor means having wall means defining an air suction chamber havingan open wall portion;

said conveyor means including movable, endless, flexible drive membersand a plurality of slats extending between said drive members with saidslats substantially closing said open wall portion of said suctionchamber, said slats defining air suction openings extending between theex ternal surface thereof and the interior of said suction chamber;

movable, endless, flexible, backup means disposed adjacent said conveyormeans for creating a substantially airtight cover over an articledisposed on and being conveyed by said slats, said endless backup meansincluding endless flexible drive elements and an airtight, wide, endlessflexible membrane extending loosely between said pair of endlesselements, the opposite edges of said membrane being maintained inairtight engagement with the edges of said slats throughout theconveying reach of said conveyor means; and

air suction means connected to said air suction chamber for creating asuction therein to cause said flexible membrane to create an airtightcover over an article disposed on said slats for holding said article onsaid slats as it is conveyed by said conveyor means.

2. A conveyor apparatus according to claim 1, wherein said conveyormeans includes an elastic plate secured to the external surface of saidslats, said air suction openings extending through both said slats andsaid elastic plate.

3. A conveyor apparatus according to claim 1, wherein said endlessflexible membrane is constructed at least in part of a flexiblerubberlike material.

4. A conveyor apparatus according to claim 1, wherein said conveyormeans and said backup means both include elongated inclined portionsdisposed adjacent one another for enabling articles to be conveyedbetween different elevations.

5. A conveyor apparatus according to claim 1, wherein said endlessflexible drive members and said endless flexible drive elements compriseendless chainlike members disposed in engagement with rotatable toothedwheels for movably supporting said slats and said membrane.

6. A conveyor apparatus according to claim 1, wherein said wall meansincludes an elongated channel-shaped member disposed between andextending longitudinally of said endless drive members, the underside ofthe conveying reach of said conveyor means being disposed closelyadjacent the open side of said channel-shaped member whereby said slatsextend across said channel-shaped member and substantially close saidopen side thereof.

1. A conveyor apparatus, comprising: conveyor means having wall meansdefining an air suction chamber having an open wall portion; saidconveyor means including movable, endless, flexible drive members and aplurality of slats extending between said drive members with said slatssubstantially closing said open wall portion of said suction chamber,said slats defining air suction openings extending between the externalsurface thereof and the interior of said suction chamber; movable,endless, flexible, backup means disposed adjacent said conveyor meansfor creating a substantially airtight cover over an article disposed onand being conveyed by said slats, said endless backup means includingendless flexible drive elements and an airtight, wide, endless flexiblemembrane extending loosely between said pair of endless elements, theopposite edges of said membrane being maintained in airtight engagementwith the edges of said slats throughout the conveying reach of saidconveyor means; and air suction means connected to said air suctionchamber for creating a suction therein to cause said flexible membraneto create an airtight cover over an article disposed on said slats forholding said article on said slats as it is conveyed by said conveyormeans.
 2. A conveyor apparatus according to claim 1, wherein saidconveyor means includes an elastic plate secured to the external surfaceof said slats, said air suction openings extending through both saidslats and said elastic plate.
 3. A conveyor apparatus according to claim1, wherein said endless flexible membrane is constructed at least inpart of a flexible rubberlike material.
 4. A conveyor apparatusaccording to claim 1, wherein said conveyor means and said backup meansboth include elongated inclined portions disposed adjacent one anotherfor enabling articles to be conveyed between different elevations.
 5. Aconveyor apparatus according to claim 1, wherein said endless flexibledrive members and said endless flexible drive elements comprise endlesschainlike members disposed in engagement with rotatable toothed wheelsfor movably supporting said slats and said membrane.
 6. A conveyorapparatus according to claim 1, wherein said wall means includes anelongated channel-shaped member disposed between and extendinglongitudinally of said endless drive members, the underside of theconveying reach of said conveyor means being disposed closely adjacentthe open side of said channel-shaped member whereby said slats extendacross said channel-shaped member and substantially close said open sidethereof.